When transporting perishable or temperature-sensitive items for personal or industrial purposes or when undertaking short-term or long-term storage of such items, some type of cooling or refrigeration apparatus is normally used to retain the items at a desired temperature. For example, milk, ice cream, cheese, meats, and similar perishable food items are normally transported long distances using refrigerated trucks or similar vehicles, and are then maintained in refrigerated areas of a store until sale. In situations where use of a refrigerated vehicle or storage area is impractical or unnecessary, various temperature-sensitive items can be transported inside an insulated, temperature-regulated container accompanied by a refrigerant such as dry ice. Typically, use of refrigerants and sophisticated vehicles and/or containers is economically prohibitive, except for large-scale use, and even in such instances, technologically advanced systems are prone to damage or malfunction.
When transporting or storing temperature-sensitive items for personal use, such as when packaging perishable food items for lunch at work or school, during travel, or for a picnic or other recreational event, it is common to use technologically simpler means to maintain the temperature of the perishable items until use. The most common objects utilized for such a purpose include insulated coolers within which the objects are placed, such that the walls and lid of the cooler prevent the transfer of heat between the ambient environment and the interior of the cooler. When longer-term storage is desired, reusable, sealed packages containing a freezable substance can be placed in a freezer until the substance is frozen, then placed inside the cooler to maintain the cooler's interior at a desired temperature! until the freezable substance has melted. Combined with the insulating properties of the cooler, use of one or more packages of frozen material placed among the contents can maintain a favorable temperature within the cooler for several hours or more, however the temperature maintenance provided by discrete packages of frozen materials within a container is often uneven, the largest benefit being provided to objects immediately adjacent to the frozen material, while other contents may become warmer than desired.
While conventional use of sealed containers of frozen material is generally an effective method for maintaining the temperature within a cooler for short-term storage and/or transport of items, this method presents several undesirable drawbacks. Most notably, sealed packages of freezable material occupy space within the interior of a cooler or similar insulated container which reduces the available space within the container for storing items. Additionally, as a package of freezable material begins to warm while cooling the interior of a container, condensation can form on the exterior of the package, dampening the contents of the container. Further, as described above, discreet packages of freezable material are restricted to occupying a single defined space within a container, thereby providing an uneven distribution of temperature throughout the container's interior. Objects proximate to the freezable material may become extremely cold, and can possibly be chilled beyond a desirable temperature range, while objects elsewhere within a container may not benefit significantly from the presence of the freezable material.
One method by which some of these drawbacks have been overcome has included the placement of packages of freezable material, or unpackaged freezable material and/or phase-change material, within the walls of a container, sandwiched between sealed or attached layers. The entire container is placed in a freezer to freeze the sandwiched freezable material, at which point temperature-sensitive items can be placed within the container, in direct contact with the interior surfaces of the container to ensure adequate temperature regulation. However, these multi-layer containers can become worn and begin to leak materials contained within the walls especially at the points of attachment between separable parts or along sealed areas. Additionally, over time, material contained between the wall layers of such a container has a tendency to settle toward the container's base, mitigating the effectiveness of the container due to uneven distribution of freezable material and/or places within the container where such material is lacking entirely. Further, many such containers include multiple interlocking parts, hinges and similar moving and/or removable parts that are prone to damage or leakage after an extended period of use.
A need exists for a refreezable container that captures the advantages of direct contact between a cooling medium and the container's contents, while remaining simple in design and construction, thereby minimizing the potential for damage or leakage.
A need exists for a refreezable container that can be provided with unique and non-standard shapes, including bowl shapes and cylindrical shapes, for containing items not normally transportable in a temperature-regulated container, such as liquids and gels.
A further need exists for a refreezable container having a discrete cavity within each surface to contain refreezable material, prevent significant settling, and ensure that the refreezable material remains in a suitable position to substantially enclose the container.
A need also exists for a refreezable container having enhanced storage and nesting features to facilitate transport and storage of multiple containers while occupying a minimum amount of necessary space.
The present invention meets these needs.